Method for producing MTW-type zeolite

ABSTRACT

The method for producing an MTW-type zeolite according to the present invention includes: mixing a silica source, an alumina source, an alkali source, a lithium source, and water so as to obtain a reaction mixture having a composition represented by specific molar ratios; (2) adding an MTW-type zeolite which has a SiO 2 /Al 2 O 3  ratio of 10 to 500 and does not contain an organic compound, as a seed crystal, to the reaction mixture in a proportion of 0.1 to 20% by weight relative to the silica component in the reaction mixture; and (3) airtightly heating the reaction mixture, to which the seed crystal has been added, at 100 to 200° C.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.13/509,677, filed Mar. 1, 2013, now U.S. Pat No. 9,333,495, whichapplication is the 35 U.S.C. §371 National Phase Application ofInternational PCT Patent Application No. PCT/JP10/70663, filed Nov. 19,2010, which application claims the benefit of priority to JapanesePatent Application No. JP 2009-264550, filed Nov. 20, 2009, the contentsof each of which in their entirety are hereby incorporated herein byreference.

TECHNICAL FIELD

The present invention relates to a method for producing an MTW-typezeolite from a reaction mixture in which an organic compound is notused, by adding an MTW-type zeolite which does not contain an organiccompound, as a seed crystal.

BACKGROUND ART

Synthetic zeolite is a crystalline aluminosilicate and has uniformmicropores in an angstrom size resulting from the crystal structurethereof. Taking advantage of this feature, the synthetic zeolite hasbeen industrially used as a molecular sieve adsorbent which adsorbs onlythe molecules having a specific size, an adsorption separating agentwhich adsorbs molecules having high affinity, or a catalyst base agent.MTW is a designation representing the framework structure type given tozeolite ZSM-12, and zeolite having the same structure includes CZH-5,NU-13, TPZ-12, Theta-3, and VS-12. The MTW-type zeolite is used in alarge amount all over the world at present as a catalyst inpetrochemical industry. The feature of the MTW-type zeolite is in thatit has 12 membered-ring one-dimensional micropores as described in thefollowing Non Patent Literature 1. Further, the X-ray diffractionpattern showing the structural feature thereof is described in thefollowing Non Patent Literature 2.

Since the MTW-type zeolite has been conventionally produced only by amethod in which an organic ammonium ion is used as a structure-directingagent (hereinafter abbreviated as “SDA”), it has been considered thatthe use of SDA is essential in order to obtain the MTW-type zeolite.Further, since synthesized MTW-type zeolite contains SDA, it has beenconsidered inevitable that the zeolite is fired to remove SDA before itis used.

Various methods for synthesizing the MTW-type zeolite are proposed. Acommon method is a method of using organic ammonium ions, such astetraethylammonium ions, methyltriethylammonium ions, orbenzyltriethylammonium ions, as SDA. Also, at the same time, addition ofalkali metal ions, such as sodium or lithium, is essential. Such amethod is for example described in the following Patent Literatures 1 to3. According to these methods, an MTW-type zeolite having a SiO₂/Al₂O₃ratio of 20 or more can be obtained. However, the SDAs as describedabove are expensive, and most SDAs in mother liquor may be decomposedafter completion of the crystallization of the MTW-type zeolite.Further, since these SDAs are incorporated into the crystals of thezeolite to be produced, it is necessary to fire the zeolite to removethe SDAs when using the zeolite as an adsorbent or a catalyst. Theexhaust gas from the firing causes environmental pollution, and furthera large amount of chemicals is required for the detoxification treatmentof the synthetic mother liquor containing decomposition products ofSDAs. Thus, since the synthetic method of the MTW-type zeolite using SDAis not only expensive, but is a production method having a highenvironmental load, the realization of a production method in which SDAis not used and an MTW-type zeolite which is obtained by the productionmethod and does not essentially contain organic matter is desired.

CITATION LIST Patent Literature

-   Patent Literature 1: Japanese Patent Publication No. 52-16079-   Patent Literature 2: Japanese Patent Publication No. 63-31406-   Patent Literature 3: Japanese Patent Laid-Open No 60-264320-   Non Patent Literature 1: Ch. Baerlocher, L. B. McCusker, D. H.    Olson, Atlas of Zeolite Framework Types, Published on behalf of the    Commission of the International Zeolite Association, 2007, p.    232-233-   Non Patent Literature 2: M. M. J. Treacy and J. B. Higgins,    Collection of Simulated XRD Powder Patterns for Zeolites, Published    on behalf of the Commission of the International Zeolite    Association, 2007, p. 300-301

SUMMARY OF INVENTION Technical Problem

An object of the present invention is to provide a method for producingan MTW-type zeolite which does not essentially contain organic matter,specifically a method which eliminates the prior art disadvantages asdescribed above, can reduce an environmental load as much as possible,and can produce an MTW-type zeolite without using SDA and inexpensively.

Solution to Problem

A conventional method for producing an MTW-type zeolite is a method inwhich organic ammonium ions are used as SDA, and at the same time alkalimetal ions are added, as described above. However, a method of producingan MTW-type zeolite by using only alkali metal ions without using SDAhas not been known at all. The present inventors have found a method forproducing an MTW-type zeolite in which SDA is not used, by firing anMTW-type zeolite which has been synthesized using SDA to remove SDA andusing the fired MTW-type zeolite as a seed crystal. These findings haveled to the completion of the present invention.

Specifically, the present invention provides a method for producing anMTW-type zeolite comprising:

-   (1) mixing a silica source, an alumina source, an alkali source, a    lithium source, and water so as to obtain a reaction mixture having    a composition represented by the following molar ratios:-   SiO₂/Al₂O₃=12 to 200-   Na₂O/SiO₂=0.1 to 0.3-   Li₂O/(Na₂O+Li₂O)=0.05 to 0.5-   H₂O/SiO₂=10 to 50;-   (2) adding an MTW-type zeolite which has a SiO₂/Al₂O₃ ratio of 10 to    500 and does not contain an organic compound, as a seed crystal, to    the reaction mixture in a proportion of 0.1 to 20% by weight    relative to the silica component in the reaction mixture; and-   (3) airtightly heating the reaction mixture, to which the seed    crystal has been added, at 100 to 200° C.

Advantageous Effects of Invention

As described above, in the present invention, since an MTW-type zeoliteis produced from a reaction mixture which does not use SDA, by adding anMTW-type zeolite which does not contain organic matter, as a seedcrystal, the resulting MTW-type zeolite does not essentially containorganic matter. Therefore, this MTW-type zeolite does not require firingtreatment before it is used, does not require exhaust gas treatmentbecause no organic matter is produced by dehydration treatment, has asmall environmental load, and can be produced inexpensively.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an X-ray diffraction pattern of the MTW-type zeolite afterfiring for the seed crystal having a SiO₂/Al₂O₃ ratio of 50.6synthesized in Reference Example 1.

FIG. 2 is an X-ray diffraction pattern of the MTW-type zeolite afterfiring for the seed crystal having a SiO₂/Al₂O₃ ratio of 101.2synthesized in Reference Example 1.

FIG. 3 is an X-ray diffraction pattern of the MTW-type zeolitesynthesized in Example 1.

FIG. 4 is an X-ray diffraction pattern of the MTW-type zeolitesynthesized in Example 2.

FIG. 5 is an X-ray diffraction pattern of the MTW-type zeolitesynthesized in Example 3.

DESCRIPTION OF EMBODIMENTS

Hereinafter, the present invention will be described based on preferredembodiments thereof. The MTW-type zeolite synthesized according to thepresent invention does not essentially contain organic matter in thestate where it is not heat-treated. The ions which compensate thenegative charge of 4-coordinate aluminum of the aluminosilicateframework and are present outside the framework are sodium ions andlithium ions, and others which are present in micropores are only wateror a small amount of adsorbed gas. That is, since the MTW-type zeolitesynthesized according to the present invention is obtained by aproduction method in which SDA to be described below is not used, itdoes not essentially contain organic matter. The ratio of SiO₂/Al₂O₃ ofthe aluminosilicate framework is preferably in the range of 12 to 200.Further, the X-ray diffraction pattern of the MTW-type zeolitesynthesized according to the present invention is essentially the sameas the X-ray diffraction pattern of the MTW-type zeolite described inNon Patent Literature 2 as described above. From this, it is determinedthat the structural feature of the MTW-type zeolite synthesizedaccording to the present invention is the same as that of conventionalMTW-type zeolite synthesized using SDA.

One of the features of the production method of the present invention isthat a reaction mixture is prepared without adding SDA which is composedof an organic compound. Specifically, an aqueous aluminosilicate gelcontaining sodium ions and lithium ions is used as a reaction mixture.It is an essential condition that sodium ions and lithium ions areallowed to be present together with the reaction mixture of the aqueousaluminosilicate gel. Further, their mixing proportions are such that theratio Li₂O/(Na₂O+Li₂O) is in the range of 0.05 to 0.5, preferably in therange of 0.1 to 0.4. If the ratio is outside this range, impurities willbe accompanied, or the crystallinity of the MTW-type zeolite will bereduced.

Another feature of the production method of the present invention is theuse of a seed crystal. An MTW-type zeolite produced by a conventionalmethod, that is, a method in which SDA is used is fired to removeorganic matter and used as a seed crystal. A method for synthesizing anMTW-type zeolite in accordance with a conventional method is described,for example, in Patent Literatures 1 to 3 as described above, and iswell known to those skilled in the art. The type of SDA to be used isnot limited, in a method for synthesizing the MTW-type zeolite inaccordance with a conventional method. That is, the type of SDA may beany of organic ammonium ions such as tetraethylammonium ions,methyltriethylammonium ions, and benzyltriethylammonium ions asdescribed above, or may be any other type.

In the synthesis of a seed crystal, it is preferred to add alkali metalions simultaneously with the addition of SDA. It is preferred to usesodium and/or lithium ions as the alkali metal ions. Thus, once anMTW-type zeolite is synthesized, it is required to fire the MTW-typezeolite, for example, at a temperature of 500° C. or more in the air toremove SDA which is incorporated into the crystal, before using theMTW-type zeolite as a seed crystal. If the method of the presentinvention is performed using a seed crystal from which SDA is notremoved, organic matter will enter the discharge liquor after completionof the reaction. Further, the MTW-type zeolite to be produced maycontain SDA, which is contrary to the spirit of the present invention.

In the production method of the present invention, the MTW-type zeoliteobtained in accordance with the present invention can also be used as aseed crystal. The MTW-type zeolite obtained by the present inventiondoes not essentially contain an organic compound. Therefore, it has anadvantage that when it is used as a seed crystal, it needs not besubjected to firing treatment beforehand.

Both in the case of using the MTW-type zeolite obtained in accordancewith a conventional method and in the case of using the MTW-type zeoliteobtained in accordance with the present invention, the SiO₂/Al₂O₃ ratioof the seed crystal is in the range of 10 to 500, preferably in therange of 10 to 200. If the SiO₂/Al₂O₃ ratio of the seed crystal issmaller than 10, the synthesis of the MTW-type zeolite will be difficultby any methods. On the other hand, if the SiO₂/Al₂O₃ ratio is largerthan 500, the crystallization rate of the MTW-type zeolite will be veryslow, which is not efficient.

The amount of the seed crystal added is in the range of 0.1 to 20% byweight, preferably in the range of 1 to 10% by weight, relative to thesilica component in the reaction mixture as described above. Providedthat the amount added is within the above range, the amount of the seedcrystal added is smaller the better, and the amount added is determinedin consideration of a reaction rate, an effect of suppressingimpurities, and the like.

The grain size of the MTW-type zeolite seed crystal used in the presentinvention is not critical and not particularly limited in the presentinvention. It may be a size of a nanometer order or may be a size of amicrometer order. The size of the crystal of the zeolite obtained bysynthesis is generally not uniform and has a certain degree of grainsize distribution. When the crystal grain size having the maximumfrequency in the distribution is defined as the average grain size, theaverage grain size may have influence on a crystallization rate or thesize of crystals produced, but the difference in the average grain sizeof seed crystals will not cause essential trouble to the synthesis ofthe MTW-type zeolite.

The reaction mixture to which the seed crystal is added is obtained bymixing a silica source, an alumina source, an alkali source, a lithiumsource, and water so as to obtain a composition represented by thefollowing molar ratios. If the composition of the reaction mixture isoutside the following range, a target MTW-type zeolite cannot beobtained as apparent from the results of Comparative Examples to bedescribed below.

-   -   SiO₂/Al₂O₃=12 to 200    -   Na₂O/SiO₂=0.1 to 0.3    -   Li₂O/(Na₂O+Li₂O)=0.05 to 0.5    -   H₂O/SiO₂=10 to 50

A more preferred range of the composition of the reaction mixture is asfollows.

-   -   SiO₂/Al₂O₃=12 to 150    -   Na₂O/SiO₂=0.12 to 0.25    -   Li₂O/(Na₂O+Li₂O)=0.1 to 0.4    -   H₂O/SiO₂=12 to 30

The silica source used for obtaining the reaction mixture having theabove molar ratios includes silica itself and a silicon-containingcompound which can produce silicate ions in water. Specific examplesinclude wet-process silica, dry-process silica, colloidal silica, sodiumsilicate, and aluminosilicate gel. These silica sources can be usedindividually or in combination of two or more. Among these silicasources, it is preferred to use silica (silicon dioxide) in that targetzeolite can be obtained without being accompanied by an unnecessaryby-product.

As the alumina source, a water-soluble aluminum-containing compound canbe used, for example. Specific examples include sodium aluminate,aluminum nitrate, and aluminum sulfate. Further, aluminum hydroxide isalso one of the suitable alumina sources. These alumina sources can beused individually or in combination of two or more. Among these aluminasources, it is preferred to use sodium aluminate and aluminum hydroxidein that target zeolite can be obtained without being accompanied byunnecessary by-products (for example, sulfate, nitrate, and the like).

As the alkali source, sodium hydroxide can be used, for example. Notethat when sodium silicateis used as a silica source or when sodiumaluminate is used as an alumina source, sodium which is an alkali metalcomponent contained therein is considered to be NaOH at the same time,which is also an alkali component. Therefore, the above Na₂O iscalculated as the sum of all the alkali components in the reactionmixture.

As the lithium ion source, lithium salts are suitably used, includinghalides such as chlorides, bromides, and iodides and inorganic acidsalts such as nitrates and sulfates. In addition, soluble organic saltsmay be used. Further, lithium hydroxide may be used as one of thelithium ion sources. In this case, since lithium hydroxide acts not onlyas a lithium ion source but also as an alkali source, it is necessary totake not only the Li₂O/(Na₂O+Li₂O) ratio but also the optimization ofthe total alkali amount into consideration.

Any method by which a uniform reaction mixture can be easily obtainedmay be employed as the order of adding each raw material for preparingthe reaction mixture. For example, a uniform reaction mixture can beobtained by adding an alumina source and a lithium source to an aqueoussodium hydroxide solution to dissolve the sources at room temperature,followed by adding a silica source and stirring and mixing. A seedcrystal is added before adding a silica source or added while beingmixed with a silica source. Subsequently, they are stirred and mixed sothat the seed crystal is uniformly dispersed. The temperature at whichthe reaction mixture is prepared is also not particularly limited, andthe preparation may be generally performed at room temperature (20 to30° C.).

The reaction mixture containing the seed crystal is put in an airtightcontainer and heated to react it to crystallize the MTW-type zeolite.SDA is not included in this reaction mixture. Crystallizationsufficiently proceeds even while the airtight container is leftstanding. When the reaction mixture is stirred to achieve equalizationof the temperature thereof during heating, it may be subjected to mixingwith an impeller or mixing by rotation of the container. The strength ofstirring and the number of rotations may be controlled depending on theuniformity of temperature and the manner in which impurities areby-produced. Intermittent stirring may be employed instead of continuousstirring.

Both in the case of a stationary method and a stirring method, thereaction mixture is heated at a heating temperature of 100 to 200° C.,preferably 120 to 180° C., under a spontaneous pressure. If thetemperature is less than 100° C., a crystallization rate will beextremely slow, thereby reducing the production efficiency of theMTW-type zeolite. On the other hand, a temperature exceeding 200° C. isnot economical because an autoclave having high pressure resistance isrequired, and it increases the rate of impurity production. Therefore,this temperature range is not preferred. The heating time is notcritical in the present production method, and the reaction mixture maybe heated until an MTW-type zeolite having a sufficiently highcrystallinity is produced. An MTW-type zeolite having a satisfactorycrystallinity can be generally obtained by heating for about 5 to 500hours.

The crystal of the MTW-type zeolite is obtained by the heating asdescribed above. After completion of the heating, the produced crystalpowder is separated from mother liquor by filtration, and then washedwith water or warm water, and dried. Since the MTW-type zeolite does notcontain organic matter in the dried state, it does not require firingand can be used as an adsorbent or the like if it is subjected todehydration. Further, when the MTW-type zeolite is used as a solid acidcatalyst, it can be used as an H⁺ type, for example, by exchanging Na⁺ions and Li⁺ ions in the crystal with NH₄ ⁺ ions, followed by firing.

The MTW-type zeolite obtained by the present production method can besuitably used, for example, as an adsorption separating agent in variousindustrial fields and a catalyst in petrochemical industries, using thelarge micropore size and micropore volume and solid acid characteristicsthereof.

EXAMPLES

Hereinafter, the present invention will be described in more detail withreference to Examples. However, the scope of the present invention isnot limited to these Examples. Unless otherwise specified, “%” means “%by weight”. Note that the analytical instruments used in the followingExamples and Comparative Examples are as follows.

Powder X-ray diffractometer: A powder X-ray diffractometer MO3XHF²²manufactured by Mac Science Co., Ltd., use of Cukα rays, voltage: 40 kV,current: 30 mA, scanning step: 0.02°, scanning speed: 2°/min Compositionanalyzer: ICP-AES LIBERTY Series II manufactured by Varian Inc.

Reference Example 1

A reaction mixture having a composition of8TEA₂O.3.5Li₂O.Al₂O₃.40SiO₂.640H₂O was prepared by usingtetraethylammonium hydroxide as SDA, aluminum hydroxide as an aluminasource, lithium bromide as a lithium source, and fine powder silica(Cab-O-sil, M-5) as a silica source and further adding water. Thisreaction mixture was put in an airtight container and heated at 160° C.for 5 days. The product was an MTW-type zeolite. This was fired in anelectric furnace at 550° C. for 10 hours while circulating air tosynthesize a seed crystal 1 which does not contain organic matter. TheSiO₂/Al₂O₃ ratio after firing was 50.6. The X-ray diffraction pattern ofthis MTW-type zeolite is shown in FIG. 1.

Reference Example 2

A reaction mixture having a composition of9.8TEA₂O.0.79Na₂O.Al₂O₃.80SiO₂.1040H₂O was prepared by usingtetraethylammonium hydroxide as SDA, sodium aluminate as an aluminasource, and fine powder silica (Cab-O-sil, M-5) as a silica source andfurther adding water. This reaction mixture was put in an airtightcontainer and heated at 160° C. for 8 days. The product was an MTW-typezeolite. This was fired in an electric furnace at 550° C. for 10 hourswhile circulating air to synthesize a seed crystal 2 which does notcontain organic matter. The SiO₂/Al₂O₃ ratio after firing was 101.2. TheX-ray diffraction pattern of this MTW-type zeolite is shown in FIG. 2.

Example 1

The reaction mixture having the composition described in Table 1 wasprepared by dissolving 0.30 g of sodium hydroxide in 5.8 g of distilledwater and adding thereto 0.31 g of lithium bromide monohydrate, 0.16 gof aluminum hydroxide, 0.12 g of the seed crystal 1, and 1.20 g ofsilica (Cab-O-Sil M5) in this order, followed by uniformly stirring.This reaction mixture was put in an airtight container and heated at140° C. for 7 days. The product was separated by filtration, washed withwater, and then dried at 60° C. This product was an MTW-type zeolitewhich does not contain impurities, as apparent from the X-raydiffraction pattern shown in FIG. 3. The results of the compositionanalysis were as shown in Table 1.

Example 2

The reaction mixture having the composition described in Table 1 wasprepared using the same raw materials as in Example 1, and it was heatedunder the conditions as described in the same table. The product was anMTW-type zeolite which does not contain impurities, as apparent from theX-ray diffraction pattern shown in FIG. 4. The product was as describedin Table 1.

Example 3

The reaction mixture having the composition described in Table 1 wasprepared using the same raw materials as in Example 1 except that theMTW-type zeolite seed crystal 2 synthesized in Reference Example 2 wasused, and it was heated under the conditions as described in the sametable. The product was an MTW-type zeolite which does not containimpurities, as apparent from the X-ray diffraction pattern shown in FIG.5. The composition of the product was as described in Table 1.

Example 4

The reaction mixture having the composition described in Table 1 wasprepared using the same raw materials as in Example 1 except that theamount of the seed crystal 1 added was set at 1%, and it was heatedunder the conditions as described in the same table. As a result, theproduct and the composition thereof were as described in Table 1.

Examples 5 to 13

The reaction mixtures each having the composition described in Table 1were prepared using the same raw materials as in Example 1, and theywere heated under the conditions as described in the same table. As aresult, the products and the compositions thereof were as described inTable 1.

TABLE 1 Seed crystal Composition of reaction mixture Amount HeatingProduct SiO₂/ Na₂O/ Li₂O/ H₂O/ SiO₂/ added *¹ Temperature Time SiO₂/Na₂O/ Li₂O/ Example Al₂O₃ SiO₂ (Na₂O + Li₂O) SiO₂ Al₂O₃ (wt %) (° C.)(day) Zeolite Al₂O₃ Al₂O₃ Al₂O₃ 1 20 0.188 0.286 16 50.6 10 140 7MTW-type 19.2 0.42 0.46 2 40 0.188 0.286 16 50.6 10 140 7 MTW-type, 36.60.80 0.47 very small amount of layered silicate 3 20 0.188 0.286 16101.2 10 140 7 MTW-type 17.8 0.68 0.34 4 20 0.188 0.286 16 50.6 1 140 24MTW-type 19.0 0.50 0.49 5 60 0.188 0.286 16 50.6 10 140 14 MTW-type — —— 6 100 0.188 0.286 16 50.6 10 140 14 MTW-type, — — — very small amountof layered silicate 7 15 0.188 0.286 16 50.6 10 140 7 MTW-type 17.8 0.360.50 8 30 0.188 0.286 16 50.6 10 140 7 MTW-type 33.0 0.52 0.60 9 400.150 0.286 16 50.6 10 140 10 MTW-type — — — 10 40 0.225 0.286 16 50.610 140 7 MTW-type, — — — very small amount of ZSM-5 11 20 0.188 0.150 1650.6 10 140 7 MTW-type — — — 12 20 0.188 0.320 16 50.6 10 140 7 MTW-type— — — 13 40 0.188 0.444 16 50.6 10 140 7 MTW-type, — — — very smallamount of layered silicate *¹ Amount of silica relative to reactionmixture

Comparative Example 1

The reaction mixture having the composition described in Table 2 wasprepared using the same raw materials as used in Example 1 and the seedcrystal 1 except that lithium bromide monohydrate was not added, and itwas heated under the conditions as described in the same table. As aresult, the product was as described in Table 2.

Comparative Examples 2 and 3

The reaction mixtures each having the composition described in Table 2were prepared using the same raw materials as used in Example 1 and theseed crystal 1, and they were heated under the conditions as describedin the same table. As a result, the product was as described in Table 2.

Comparative Example 4

The reaction mixture having the composition described in Table 2 wasprepared using the same raw materials as used in Example 1 except that aseed crystal was not added, and it was heated under the conditions asdescribed in the same table. As a result, the product was as describedin Table 2.

TABLE 2 Seed crystal Composition of reaction mixture Amount HeatingComparative SiO₂/ Na₂O/ Li₂O/ H₂O/ SiO₂/ added *¹ Temperature TimeProduct Example Al₂O₃ SiO₂ (Na₂O + Li₂O) SiO₂ Al₂O₃ (wt %) (° C.) (day)Zeolite 1 40 0.188 0 16 50.6 10 150 4 ZSM-5 2 40 0.188 0.600 16 50.6 10150 4 Lithium silicate 3 10 0.188 0.286 16 50.6 10 140 7 Mordenite 4 400.188 0.286 16 — 0 140 7 Layered silicate *¹ Amount of silica relativeto reaction mixture

The invention claimed is:
 1. A method for producing an MTW-type zeolite,comprising: (1) mixing an alumina source, an alkali source, a lithiumsource, and water so as to obtain a reaction mixture; (2) adding a seedcrystal of a Beta-type zeolite before adding a silica source or addingthe seed crystal of the Beta-type zeolite while being mixed with asilica source, to the reaction mixture in a proportion of 0.1 to 20% byweight relative to the silica component in the reaction mixture, mixingand stirring, wherein the Beta-type zeolite of the seed crystal has aSiO₂/Al₂O₃ ratio of 10 to 500 and does not contain an organic compound;and wherein the resulting reaction mixture has a composition representedby the following molar ratios: SiO₂/Al₂O₃=12 to 200 Na₂O/SiO₂=0.1 to 0.3Li₂O/(Na₂O+Li₂O)=0.05 to 0.5 H₂O/SiO₂=10 to 50; and (3) air tightlyheating the reaction mixture, to which the seed crystal of the Beta-typezeolite has been added, at 100 to 200° C.